The Mind-Gut Connection: How the Hidden Conversation Within Our Bodies Impacts Our Mood, Our Choices, and Our Overall Health

by Emeran Mayer

Even in healthy pregnancies, maternal gut bacteria—most of them beneficial—have turned up in umbilical cord blood, amniotic fluid, meconium, and on the placenta, according to recent work. As the time of delivery nears, the vaginal microbiota changes a great deal. The diversity of microbial species decreases, and a lactobacillus species normally found in the small intestine becomes more prevalent. During birth, a baby born naturally is exposed to the mother’s vaginal microbiota, including this lactobacillus species, providing the key source of microbes to colonize the infant’s gut. In this way, your mother’s distinct set of vaginal microbes formed the basis for your own distinct pattern of gut microbes, and will for the rest of your life. The mother’s microbes also supply our newborns with a key piece of its metabolic machinery, giving the baby the ability to digest the milk sugars and special carbohydrates in breast milk.